Controls Library: Extended ListView with Column Mapping

using dwf.tool;
using Gdk;
using Gtk;
using System;
using System.Collections.Generic;

namespace dwf.gui
{
    public class PEditor : Gtk.HBox, IPEditor
    {
        protected Dictionary<string, object> CacheControls = new Dictionary<string, object> ();
        protected IPCellEditor currentEditor;
        protected bool _changed;
        protected object _value;
        protected Widget _control;
        protected Button _drop;
        protected Button _dropEx;
        protected bool _dropDownVisible = true;
        protected bool _dropDownAutoHide = false;
        protected bool _dropDownExVisible = false;
        protected ToolWindow _dropDown;
        protected EventHandler valueChanged;
        protected EventHandler _dropDownClick;
        protected EventHandler _dropDownExClick;
            
        public PEditor ():base(false, 4)
        {
            _drop = new Button ();
            _drop.Label = "...";
            _drop.WidthRequest = 25;
            _drop.Clicked += DropClicked;
            _dropEx = new Button ();
            _dropEx.Label = "~";
            _dropEx.WidthRequest = 25;
            _dropEx.Clicked += DropExClicked;
        }

        public bool Enabled
        {
            get;
            set;
        }

        private void DropClicked (object sender, EventArgs e)
        {
            if (_dropDownClick != null)
                _dropDownClick (this, e);
            ShowDropDown ();
        }

        private void DropExClicked (object sender, EventArgs e)
        {
            if (_dropDownExClick != null)
                _dropDownExClick (this, e);
        }

        public event EventHandler DropDownClick
        {
            add{ _dropDownClick += value;}
            remove{ _dropDownClick -= value;}
        }

        public event EventHandler DropDownExClick
        {
            add{ _dropDownExClick += value;}
            remove{ _dropDownExClick -= value;}
        }

        protected override bool OnExposeEvent (EventExpose evnt)
        {
            return base.OnExposeEvent (evnt);
            //if (_dropDownVisible)
            //  CtrlService.PaintDropDown (e.Graphics, GetDropDownRectangle (), PCellDisplayState.Default);

        }

        protected override void OnSizeRequested (ref Requisition requisition)
        {
            base.OnSizeRequested (ref requisition);
            requisition.Height = 25;
        }

        public IPCellEditor CurrentEditor
        {
            get { return currentEditor; }
            set { currentEditor = value; }
        }

        public event EventHandler ValueChanged
        {
            add { valueChanged += value; }
            remove { valueChanged -= value; }
        }

        protected virtual void OnValueChanged (EventArgs ea)
        {
            _changed = true;
            if (currentEditor != null)
            {
                if (_control is TextView && !((TextView)_control).Editable)
                {
                    ((TextView)_control).Buffer.Text = currentEditor.FormatValue (_value) as string;
                }
                else if (_control is Entry && !((Entry)_control).IsEditable)
                {
                    ((Entry)_control).Text = currentEditor.FormatValue (_value) as string;
                }
            }
            
            if (DropDown != null && DropDown.Visible && !(DropDown.Target is TextView))
                DropDown.Hide ();
            
            if (valueChanged != null)
            {
                valueChanged (this, ea);
            }
        }
        
        public void RemoveAll ()
        {
            foreach (Widget w in base.AllChildren)  
                this.Remove (w);
        }

        public object EditControl
        {
            get { return _control; }
            set
            {
                if (value == _control)
                    return;
                RemoveAll ();
                _control = value as Widget;
                if (_control == null)
                    return;
                _control.Visible = true;
                this.PackStart (_control, true, true, 0);
                if (_dropDownVisible)
                    this.PackStart (_drop, false, false, 0);
                if (_dropDownExVisible)
                    this.PackStart (_dropEx, false, false, 0);
                _control.GrabFocus ();
            }
        }

        public bool DropDownExVisible
        {
             get { return _dropDownExVisible; }
            set
            {
                _dropDownExVisible = value;
            }
        }

        public bool DropDownAutoHide
        {
             get { return _dropDownAutoHide; }
            set
            {
                _dropDownAutoHide = value;
            }
        }

        public bool DropDownVisible
        {
            get { return this._drop.Visible; }
            set
            {
                if (_drop.Visible == value)
                    return;
                _drop.Visible = value;
            }
        }

        public ToolWindow DropDown
        {
            get { return _dropDown; }
            set
            {
                if (_dropDown == value)
                    return;
                _dropDown = value;              
            }
        }

        public override void Dispose ()
        {
            base.Dispose ();
            foreach (KeyValuePair<string, object> kv in CacheControls)
                if (kv.Value is IDisposable)
                    ((IDisposable)kv.Value).Dispose ();
            CacheControls.Clear ();
        }

        public virtual object Value
        {
             get {  return _value; }
            set
            {
                if (_value == value)
                    return;
                _value = value;
                OnValueChanged (null);              
            }
        }

        public Color BackColor
        {
             get { return base.Style.Background (StateType.Normal); }
            //set { base.Style.Background = value; }
        }

        private void OnButton1Click (object sender, EventArgs e)
        {
            if (_dropDown != null)
            if (!_dropDown.Visible)
                ShowDropDown ();
            //else _dropDown.Close();
        }

        private void OnButton2Click (object sender, EventArgs e)
        {
            Value = null;
        }

        private void ShowDropDown ()
        {
            if (_dropDown != null)
            {
                if (!_dropDown.Visible)
                if (_dropDown.Allocation.Width < this.Allocation.Width)
                    _dropDown.Resize (this.Allocation.Width, 200);  
                _dropDown.Show (this, new Point (0, this.Allocation.Height));
            }
        }

        public object GetCacheControl (string name, Type t)
        {
            object o = null;
            if (!CacheControls.ContainsKey (name))
            {
                o = ReflectionAccessor.CreateObject (t, true);
                CacheControls.Add (name, o);
            }
            else
                o = CacheControls [name];
            return o;
        }

        public bool IsValueChanged
        {
            get { return _changed; }
            set { _changed = value; }
        }

        public IPCell Cell { get; set; }

        public System.Drawing.Point Location { get; set; }
    }
}